Truss



Feb. 11, 1969 EZELL 3,426,498

TRUSS Filed July 5, 1966 Sheet of 5 19 22 2 22 2m 22 21, 41 l /2; 23 2 23; 2 3423 14L I W\ 31 W1 /31\ 31/ Nm 1\ 31 FIG! INVENTOR. 54 1 ARRY ELMER EZELL ATTORNEYS Feb. 11, 1969 H. E. EZELL 3,426,498

TRUSS Flled July 5,. 1966 l Sheet 5 of E INVENTOR.

157 HARRY ELMER EZE LL ATTORBLEYS H. E. EZ ELL Feb. 11, 1969 TRUSS Sheet 3 of 5 Filed July 5, 1966 12 1 W MT FIGS- INVENTOR. HARRY ELMER BY 7, J M

EZELL ATTORNEYS Filed July 5, 1966 Feb. 11, 1969 H. E. EZELL 3,426,498

TRUSS Sheet 5 of 5 A770/P/VEV5 United States Patent 3 Claims ABSTRACT OF THE DISCLOSURE A truss having horizontally extending upper and lower chords and a web extending between and connecting together said chords. The web includes a series of first web members each extending downwardly and away from the centerline of the truss and including upper and lower leg portions positioned respectively on the upper surface of the upper chord and the lower surface of the lower chord, side leg portions extending between and connecting together the upper and lower leg portions on opposite sides of said upper and lower chords, and upper and lower bearing members extending between said side leg portions adjacent the lower surface of the upper chord and the upper surface of the lower chord. A series of second web members are connected to the first web members, and each extends downwardly and toward the centerline of the truss. The second web members extend between and connect together the upper and lower bearing members of adjacent ones of the first web members.

This application is a continnation-in-part of my copending application, Ser. No. 322,674, filed Nov. 12, 1963, now abandoned.

In the past various forms of trusses have been used in structures such as buildings, bridges, piers, and the like. These trusses are used to support ceilings, floors, decking and, indeed, sometimes the walls of a structure. Trusses, in the past, have usually been made from metal in which the chords or flanges of the truss are joined by an integral web or by a web which is welded to the chords forming what is known as a bar joist. Such metal trusses, therefore, must be fabricated at the factory and, when used, must be welded, bolted or riveted to other structural members by metal workers. Thus, in smaller structures such as housings, prefabricated trusses have usually been entirely of wood and have required walls or other support at relatively short intervals along the length of each beam. When, however, the metal trusses are used for supporting wooden decking, flooring, ceilings or the like, bolts, screws, straps, clevises and the like have been employed to secure the wooden structure to the metal of the truss.

In some instances, the prior art practices include the addition of a nailable member attached to the metal joist and to which the decking is nailed. These arrangements, of course, add weight to the joist thereby requiring a heavier, stronger joist, and increase the time required to make an installation. This increases the cost of a building.

Some effort, in the past, has been made to provide trusses produced from both metal and wood; however, these trusses have been expensive and must be prefabricated prior to shipment. These composite metal and wooden trusses of the prior art also have involved the drilling of holes in wood, the building of multi-piece, welded rod structures and the gluing of wood together. Thus, these prior art wood and metal trusses, while filling a need in the construction field for such a composite truss, do not lend themselves to fabrication on the job and do not materially reduce the cost with respect to the metal trusses.

Patented Feb. 11, 1969 "ice Briefly, the present invention, which overcomes the difiiculties described above, includes a truss having a pair of wooden chords disposed in essentially parallel relationship in a common plane. A web between the two chords is formed from a plurality of short sections of relatively light weight inexpensive, metal straps or rods which are interconnected adjacent the chords and diverge from each other for joining the two chords together. The metal rods are each pre-formed to provide sidewise opening hooks on the ends for extending partially around each of the chords and, at the same time, interlock with the next adjacent metal rod. In certain of the embodiments, one or both of the wooden chords may be replaced by metal bars or rods which may, if desired, be secured to the web rods by welding.

Accordingly, it is an object of the present invention to provide a composite truss which may be easily and quickly assembled from a plurality of parts, immediately prior to the utilization of the truss.

Another object of the present invention is to provide an inexpensive lightweight truss which is suitable for utilization in the construction of small dwellings and in which the chords are capable of receiving nails so that decking, flooring or other nailable materials may be secured to the truss by utilizing conventional nails.

Another object of the present invention is to provide a composite truss formed of wood and metal in which the wood requires no holes or other apertures which reduce the strength of the Wood.

Another object of the present invention is to provide a truss which is light in weight and yet is relatively strong and will support a considerable amount of weight.

Another object of the present invention is to provide a truss which is inexpensive to manufacture, durable in structure, and efficient in operation.

Other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views and wherein;

FIG. 1 is a side elevational view of a composite truss constructed in accordance with the present invention;

FIG. 2 is an enlarged fragmentary perspective view of a portion of the truss shown in FIG. 1;

FIG. 3 is a partial perspective view of a modified form of the present invention;

FIG. 4 is a side elevational view of one of the Web rods of the truss shown in FIGS. 1 and 2;

FIG. 5 is a side elevational view of a modified form of the present invention;

FIG. 6 is a view similar to FIG. 2 and showing the truss illustrated in FIG. 5;

FIG. 7 is a perspective view of one of the web rods of the truss shown in FIGS. 5 and 6';

FIG.8 is a transverse cross-sectional view showing a modified form of the truss illustrated in FJGS. 5 and 6;

FIG. 9 is a partial side elevational view of another modified form of the invention;

IFIG. 10a is an isometric view of a compression memllger of the web of the form of the invention shown in -FIG. 10b is an isometric view of a tension member of the web of the form or the invention shown in FIG. 9;

FIG. 11 is a partial isometric view of the form of the invention shown in FIG. 9;

FIG. 12 is an isometric view of an end support utilized with the form of the invention shown in FIG. 9;

FIG. 13 is a partial side elevational view of a modified form of the invention.

Referring now in detail to the embodiment chosen for the purpose of illustrating the present invention, it being understood that in its broader aspects, the present invcntion is not limited to the exact details herein depicted, numeral denotes generally the upper or major chord of the truss illustrated in FIGS. 1 and 2. Disposed parallel to and spaced below the major or upper chord 10 is the lower or minor chord 11. The two chords 10 and 11 are disposed in the same plane with each other, the ends 12 and 13 of the lower chord 11 being spaced inwardly from the ends 14 and 15 of the upper chord 10 by an equal amount.

As best seen in FIG. 2, the upper chord 10 includes a crossbeam 16 which, preferably, is rectangular in cross section even though other configurations for crossbeam may be employed without departing from the scope of the present invention. Usually, the crossbeam 16 is formed from a conventional two-by-four piece of wood which is readily available throughout the country. Hence, crossbeam 16 has a pair of opposed sides 17 and 18, an upper surface 19 and a lower surface 20.

'In the embodiment here disclosed, the crossbeam 16 has its wider sides namely, top surface 19 and bottom surface 20 disposed in horizontal planes, even though it will be understood by those skilled in the art that the crossbeam 16 may have either its shorter sides 17 and 18 or its wider sides disposed in horizontal planes.

Along the top surface 19 of crossbeam 16 are a plurality of fiat, alternately long and short, rectangular plates or blocks 21 and 22 disposed in spaced tandem relationship. The long plates 21 and the short plates 22 are fixed to the crossbeam 16 by means of nails, bolts, screws, glue, or other adhesive. It will be seen in FIG. 2 that the width of the plates 21 and 22 correspond to the width of the crossbeam 16 so that the sides of plates 21 and 22 are in the same vertical planes with sides 17 and 18. The plates 21 and 22, however, are substantially less thick than the crossbeam 16, being preferably formed from conventional five-eighths thickness wooden board.

The plates 21 and 22 are aranged alternately throughout the length of the crossbeam 16, there being provided a space between the end of each long plate 21 and its adjacent short plate 22 so that these opposed ends define, with the upper surface 19 of the crossbeam 16, a U- shaped upwardly opening channel or groove 23 which extends transversely across the chord 10'. The construction of chord 10 is such that the upwardly opening transverse grooves 23 are disposed in pairs along the upper surface of chord 10, the grooves 23 in each pair being spaced apart by a short plate '22. Preferably, since the truss, here disclosed, is symmetrical, the chord 10 is of such a length that a plate 2-1 terminates adjacent each of the ends 14 and 15.

It will readily be seen that the channels or grooves 23 can be formed by dadoing the wooden chord itself. In such case it would of course be desirable to use a thicker piece of wood for the chord 10 so that the desired strength would be obtained after the dadoes are cut.

The lower chord 11 is formed in substantially the identical manner as the upper chord 10, except that the plates 27 and 28, which correspond respectively to the plates 21 and 22 are secured on the lower surface 29 of the crossbeam 30, thereby providing transverse grooves 31 which open downwardly. Furthermore, the transverse grooves 31 are staggered in pairs with respect to the pairs of grooves 23 so that adjacent pairs of grooves 31 are disposed equidistantly, vertically between the adjacent pairs of grooves 23. Hence, in the embodiment shown in FIGS. 1 and 2, the end plates 32 which are disposed adjacent the ends 12 and 13 of the lower chord 11 are shortened and are approximately the same length as the shorter plates 22 and 28.

Adjacent the ends 14 and 15 of the upper chord 10 are L-shaped brackets 41. Each bracket 41, as best seen in FIG. 2, includes a base 42 and an outwardly protruding flange 43. The base 42 is provided with a pair of holes, through which screws, such as screws 44, project for securing the base 42 flat against the side 17 of the crossbeam 16. It will be understood that, adjacent the end 14, are a pair of brackets, such as brackets 41, and adjacent the end 15 are an additional pair of brackets 41. These brackets, however, are secured on opposite sides 17 and 18 of the crossbeam 16 and are in transversely opposed relationship to each other. The flange 43 of each brackets 41 protrudes from the lower edge of the base 42 thereof and is disposed in essentially the same plane with the lower surface 20 of the crossbeam 16 so as to provide a longitudinally extending corner portion in the bracket 41 which is adapted to receive the terminal finger, such as finger 45, of a U-shaped end strap 46.

In more detail, the end strap 46 is formed from rod material which is bent to U-shape to provide a central base 47 which is substantially the same length as the transverse width of the lower chord 11. Arms 48 extend upwardly and outwardly from the base 47 and are bent adjacent their outer extremities to provide the longitudinally extending fingers, such as finger 45. The arms 48 of each end strap 46 are parallel and of equal length, being disposed in a common transverse plane which intersects the chords 10 and 11 at acute and obtuse angles, respectively. Likewise, the fingers, such as finger 45, on an end strap 46 are of equal length and are disposed parallel to each other and parallel to chord 10.

Each finger 45 is, as pointed out above, received in a corner portion of a bracket 41, there being four fingers, such as finger 45, received respectively in the four brackets such as bracket 41, in each truss of the type shown in FIGS. 1 and 2. The fingers, such as finger 45, are welded to their associated brackets, such as bracket 41 while the bases 47 of the two end straps 46 are received respectively in grooves 31 next adjacent the outermost grooves 31 of chord 11.

It is now seen that since the grooves 31 next adjacent the outermost grooves 31 are inwardly of the brackets, such as bracket 41, the end straps 46 converge down wardly so as to support by its end portions the chord 11, the lower or bottom surface 29 of crossbeam 30 resting upon the bases, such as base 47, of the two straps 46. Any appreciable endwise, i.e., longitudinal movement of the chord 11 is arrested by the plates 27, 28 on opposite sides of each base 46.

According to the present invention, a web between the two chords 10 and 11 and the end straps 46 is provided by a plurality of light weight web rods 50 which are arranged in zigzag fashion between the chords 10 and 11, the rods 50 being overlapped adjacent chords 10 and 11 and being provided with transversely opening hooks at their opposite ends for partially encompassing the crossbeams 16 and 30. All of the rods 50 between the ends are identical in shape, therefore, the structure of only one rod 50 will be described in detail.

The rod 50 is a metal member, round in cross section, having a straight central shank 51 which projects between the crossbeams 16 and 30 at an acute angle thereto. One end portion of shank 51 is bent outwardly to form an angle or bight 49 of approximately with respect to the shank 51 while the other end portion is bent in the opposite direction to another bight 49 of 90 with the shank 51 but extending in an opposite direction. Thereafter, each end portion is bent parallel to shank 51 and then back toward the axis of shank 51. Thus, the end portions are provided with U-shaped sidewise, oppositely opening hooks defined by parallel oppositely extending base bars 52 connected respectively by their inner ends to the shank 51. From the outer ends of the base bars 52, the connector bars 53 extend in opposite directions parallel to each other and shank 51. From the outer ends of connector bars 53, the head bars 54 extend parallel to each other toward the axis of shank 51, terminating therebeyond. The hooks thus formed at opposite ends of shank 51 form chord engaging members which, on adjacent shanks 51, are adapted to engage the chords and 11 from opposite sides of the chords 10 and 11.

The head bar 54 should be approximately, or slightly less than, the width transversely of crossbeams 16 and 30 while the diameter of rod 50 should be sufiiciently small for head bar 54 to be received in the grooves 23 and 31, the plane of the outer surface of each head bar 54 being below the outer surface of the plates or blocks 21, 22, 27, 28 and 32. Thus, if the rod 50 is of uniform diameter, the diameter of rod 54 should not exceed the depth of the grooves 23 and 31 which, in turn is defined by the thickness of plates 21, 22, 27, 28 and 32.

In the embodiment of FIGS. 1 and 2, the length of base rod 52, for best results, should be of a length in excess of one-half the transverse width of the chords 10 and 11, i.e., crossbeams 16 and 30, but not greater than the transverse width thereof. Preferably, the base rod 52 should exceed one-half the transverse width of crossbeams 16 or 30 by an amount slightly less than the diameter (transverse distance in event rods 50 are non-circular) of rod 50 so that the shanks 51 of adjacent rods 50 may overlap adjacent the base rods 52 while permitting the hooks of adjacent rods 50 partially to encompass, in opposite directions, the crossbeams 16 and 30. The base rod 52 should be short enough to provide a very tight, rigid fit when the shanks 51 are overlapped.

The endmost rods 50' are shaped substantially the same as the rods 50 described above; however, the rods 50 bear a larger stress than the rods 50 and should be of a larger diameter than the rods 50. Also, the hook adjacent the end member 46 is not secured by overlapping with another rod; so, the head bar 54 is longer than similar head bars and is bent inwardly to provide a retaining finger 54 over the edge of its associated chord 10 or 11.

The length of connector bars 53 i.e., the distance from base bar 51 to head bar 54, should be approximately equal to, or slightly greater than, the height of crossbeam 16 or 30 divided by the sine of the angle or subtended between the shank 51 and the chords 10 and 11. The angle a is usually approximately 60 whereby adjacent rods 50 form, with the included portion of the chords 10 or 11, an isosceles triangle.

In producing the truss of FIG. 1 and FIG. 2, the rods are initially produced in the form shown in FIG. 4. Also, the end straps 46 are fabricated and the fingers 45 thereof welded to their respective brackets 41. This of course can be accomplished at a plant.

The rods 50 and straps 46 occupy little space and may therefore be readily and easily shipped to a job in small packages.

The chords 10 and 11 are, if desired, produced on a job by nailing or otherwise securing the plates 21, 22, 27, 28 and 32 to their crossbeams 16 and 30. Thus, chords 10 and 11 are produced. As stated above, the grooves 23 or 31 can be cut into the chords themselves, which would be quite simple using a hand power saw.

In final assembly, the chords 10 and 11 are arranged parallel to each other, and the rods 50 are laid successively therebetween, the rods 50 each being placed with its connector bar 53 on one side of the chord 11, and its other connector bar 53 on the other side of the chord 10.

The webbing is formed by placing the first rod 50 in the center of the truss. One hook is placed over the chord 10 with its head bar 54 received in the appropriate groove 23, then the opposite hook is placed in its appropriate groove 31. The second rod 50 is then put into place by passing the shank 51 behind the shank 51 of the previously installed rod 50, and placing the hook on the chord 10 from the opposite side, the head bar 54 being received in the appropriate groove. Next, the opposite end is pulled, using the rod itself as a lever, and the rod is bent enough to engage the opposite hook with its chord in its appropriate groove in the chord 11. The next rod 50 is then installed in the same manner, and so on to the end of the truss. Rods 50 are similarly installedin the opposite direction until the web is completely formed.

Next, the rods 50' are installed, the two rods 50' being installed in a manner similar to that described for the rods 50. After the rods 50' are installed, the finger 54' is bent up to hold the head bar 54 in place.

The end straps 46 (which, it will be remembered, have brackets 41 welded thereto) are now installed by position ing the bases 47 thereof in the second grooves 31 from ends 12 and 13, and by aflixin-g the brackets 41 to sides 17 and 18 adjacent ends 14 and 15.

This means of construction places an intersection of two of the rods 50 adjacent the upper chord on the centerline of the truss. Since maximum deflection of a beam, or truss, is generally about in the center of the beam, this construction is desirable to give maximum support at the middle of the truss.

SECOND (EMBODIMENT The second embodiment of the invention is illustrated in FIG. 3 and includes a chord member a having a plurality of grooves 23a. Rod members 50a are formed the same as the previously described rods 50, having a hook on each end thereof, the hooks opening in opposite directions.

The groove 23a in the chord 10a is wider than the groove 23. The groove 23a receives two head bars 54a; hence, the groove 23a must be wide enough to accommodate both bar-s 5 4a. Rather than being overlapped, the rods 50o are placed adjacent one anothei with only the head bars 54a abutting. To give added strength to this construction, the head bars 54a are welded together, as indicated at W.

Since the shanks 51a are not overlapped, the head bars 54a have fingers 54b bent inwardly to hold the hook on the chord member 10a.

Though only a portion of a truss is shown in FIG. 3, it will be understood that a plurality of rods 50a are zigzagged between two chord members to provide a truss similar to the truss previously described.

THIRD EMBODIMENT The third embodiment is illustrated in FIG. 5, 6 and 7 and includes an upper chord 110 which is substantially identical to chord 10, the chord 110 including a crossbeam 116 having fiat opposed sides 117 and 118, flat upper or top surface 119 and a flat bottom surface 120. Along the top surface 119 are the plates or blocks 121 and 122 the ends of which are spaced apart to provide the grooves 123 arranged in adjacent pairs transversely parallel to each other.

The bottom chord 111 comprises a pair of adjacent parallel cylindrical metal crossbars v130 having a space 129 therebetween. Chord 111 is shorter than chord 110 and is disposed parallel to and below chord 110, the ends 112 and 113 of chord 11 1 terminating inwardly of ends 114 and of chord 110.

The web of the modified truss is formed of metal rods 150, the outermost rods 150 interlocking with end straps 146 at the opposite ends of the truss. Each end strap 1 46 is a V-shaped member having upwardly diverging arms 148 and 1 4-8' joined at their lower ends. by a bent portion or bight 147. The upper end of the outer arm 148 is bent outwardly to provide a finger 1'45 disposed below and parallel to chord 110, the finger extending toward its associated end 114 or 115. A bracket or securing plate 141, which is a flat rectangular member, is welded by one surface to finger 145 and is secured fla-t against bottom surface '120 by screws 144 which project through appropriate holes in bracket 145 and into crossbeam 11:6. The outer end of bracket 114 terminates slightly inwardly of its associated end 11 4 or 115.

The upper end of the other or inner arm 148' is provided with a sidewise opening hook having a base bar 152 connected to the end of arm 148 by an angle or bi-ght 149. A connector bar 153' extends from the end of base bar 152' and is provided at its upper end with a head bar 154 disposed parallel to base bar 152' and perpendicular to connector bar 153.

The rods 150 each include a pair of upwardly diverging shanks 151 joined at their lower ends by a bight or bend 157. The upper ends of shanks 151 of each rod 150 are respectively provided with opposed inwardly or sidewise opening hooks. Each hook includes a base bar 152, a connector bar 153 and -a head bar 154, arranged in the same manner as the bars 52, 53 and 54 of the preceding embodiment, the head bars 154, 154 being adapted to be received in the grooves 123 between plate or blocks 12 1 and 122.

The assembly of the third embodiment is quite simple. =F-irs-t, a web rod 1'50 is placed so that one of its shanks 151 extends from the central portion of the top chord 110, its hook extending partially around the chord 110 from one side so that the top bar 1 54 is received appropriately in its groove 1 23. The other shank 151 of the web rod 150 is also positioned so that its head bar C154 is appropriately received in a groove 123. Thereafter, a second web rod 150 is positioned in place by first inserting its top bar 154 in a groove 123 adjacent the groove 123 which received the first hook of the preceding web rod 150. Thereafter, the shank 151 of this second web rod 150 is passed over the shank of the first web rod 150 and is utilized as a lever so as to urge the bights 149 into close proximity with each other, as the hook on the other shank 151 is sprung out of place sufliciently to pass the chord 1'10 and engage chord 1 from a side opposite the side of engagement of the other hook thereof. This operation is repeated from both sides of the first web rod 150 until the web is completed, except for the end straps 146. Thereafter, the end straps 146 are installed in the manner previously described for the web rods 150, the brackets 141 being secured in place by screws 144.

Next, the cross-bars 130 are placed appropriately along opposite sides of the bights 147 and 157, the bights 147 and 157 being urged into alignment with each other. Next, the bights 147 and 157 are welded in place against the crossbars 130.

The truss of the third embodiment lends itself quite well to being prestressed. The prestressing may be accomplished by providing a jig into which the end straps 146 and rods 150 are placed immediately prior to the time the crossbars 134} are secured on opposite sides of bights 147 and 157. The purpose of such a jig is to urge the bottom portions of rods 150 and straps 146 (i.e., the bights 147, 157) toward each other and thereby impart a slight upwardly convex curvature to the crossbeam 116. With the rods 150 and end straps 146 so held by the jig, the crossbars 130 are welded in place, as aforesaid. The truss of the first embodiment may be prestressed in like manner by reducing the spacing between the grooves 31.

The advantages of prestressing a truss are understood by those skilled in the art and hence requires no elaboration here; however, it is significant to note that, in the third embodiment, the metal portion of the truss will withstand the tension and compression forces exerted thereon to a greater extent than the wooden chord 110 can withstand shearing and bending moments along its central portion. Therefore, the prestressing of chord 110 permits the metal structure therebeneath to carry a disproportionately greater share of the load applied to chord 110 in a downward direction.

FOURTH EMBODIMENT The fourth embodiment is shown in FIG. 8. This is very similar to the third embodiment described above, except that angle irons 230 are used in place of the round rods 130. The angle irons 230 have the rods 150 sandwiched between two flanges of the opposed angles.

This construction gives a flat surface to which can be attached metal plates or the like. It is contemplated that,

in this embodiment, the metal chord would be at the top, and the wooden chord 218 would be at the bottom. Therefore, the flat metal surface formed by the angle irons 230 would provide a convenient surface to receive plates of a metal roof, while the wooden chord 218 would provide a nailable surface to receive ceiling material of fiber board or other nailable material.

FIFTH EMBODIMENT The fifth embodiment is shown in FIGS. 9-11 and includes an upper wooden chord 310 and a lower wooden chord 311. The wooden chords of this embodiment are not slotted as shown in the previous embodiments, and the ends 312 and 314 of the upper chord 310 rest on bearing supports 315 and 316. The web 318 extending between the upper and lower chords 310 and 311 comprises a series of two basic elements; the compression element 319 and the tension element 320.

The compression element 319 is cnstructed from an elongate bar that is usually circular in cross section. The bar is formed in the shape of an elongate closed rectangle which includes side legs 321 and end legs 322. Bearing bars 324 are attached to the side legs 321. Bearing bars 324 are displaced inwardly of end legs 322 and disposed parallel thereto to form a rectangular opening 325 at the end of each compression element 319. The bearing bars 324 are positioned on opposite sides of the side legs 321 and are attached thereto by welding.

The tension element 320 is constructed from a flat elongate bar and formed in a Z-shaped configuration. The tension element 320 comprises a tension leg or center leg 326, bearing legs 328 disposed at each end of the center leg 326 and extending at an angle of approximately from the center leg 326, and locking legs 329 extending at an angle from the bearing legs 328. A locking bar 330 is connected to each locking leg 329 and is disposed parallel to and displaced from the bearing legs 328. Bearing legs 328 extend in opposite directions from the compression leg 326 of the compression element 319, at approximately 90 angles therefrom, and locking legs 329 extend from the bearing legs at an angle of approximately 60, thereby forming a general Z-shaped configuration. The locking bars 330 are attached to the locking legs 329 a distance extending perpendicular from the bearing legs 32% which is approximately equal to the thickness of the bearing bars 324 of the compression element 319. Also, the interior length of the bearing legs 328 is approximately equal to the width of the bearing bars 324 of the compression element 319. Thus, the compression elements and the tension elements can be positioned with respect to each other so that the bearing bars 324 of a compression element is disposed with one of its flat surfaces adjacent the inner portion of the bearing leg 328 of the tension element.

FIGS. 9 and 12 show end supports 335 substantially similar to that shown in FIG. 2, except that the outwardly extending flanges 336 are disposed slightly below the lower surface of the upper chord 310 and a bearing bar 338 is connected between the flanges. The bearing bar 338 is adapted to engage the tension element 320 in a manner similar to the bearing bars 324 of the compression elements.

Since end support 335 requires bolts 339 to extend through the chord 310, thereby slightly weakening the chord at this point, end support 340 can be utilized in an alternate arrangement. End support 340 is generally similar to end support 335 in that it comprises outwardly extending flanges 341 and a bearing bar 342 extending therebetween. However, the base 344 of each flange 341 is connected to the opposite base by means of 'bight 345. Bight 345 is approximately equal in its width to the width of the upper chord 310 so that the upper chord can be received between the base 344 of each flange 341, and the bight will rest on top of the chord. Of course, the bearing bar 342 extends below and across the chord when positioned in this manner, and the base 344 of each flange 341 is of a dimension such that the bearing bar 342 will be displaced downwardly from the chord 310. In order to attach the end support 340 to the chord 310, an adjustable strap 346, of U-shaped configuration, is attached to each base 344 of the end support. Threaded shanks 348 extend outwardly of each base 344 and the legs of the U-shaped strap 346 are apertured at intervals therealong. One of the apertures is positioned over the threaded shank 348 of each base 344, and a nut 349 is threaded onto the shank 348 to prevent its removal. The base of the strap 346 thereby engages the blunt end of the upper chord 310 to prohibit the end support 340 from sliding toward the centerline of the strut.

The arrangement of this embodiment of the invention is such that the tension and compression elements 319 and 320 can bepositioned on the upper chord 310 by sliding each compression element over the cord by inserting the chord through opening 325. The tension elements 320 are then positioned so that one of their locking legs 329 extends over the bearing bar 324 of a compression element, the locking bar 330 extending over the bearing bar 324 to prevent inadvertent removal of the tension element 320 of the compression element 319. The compression elements 319 are disposed so that they extend downwardly, at an angle from the upper cord 310 and their bearing bars 324 adjacent the upper chord 310 are on the upper side thereof while the bearing bar 324 to be positioned adjacent the lower cord 311 are on the lower side thereof. The bearing legs 328 of each tension element 320 are positioned so they lie flat against the surface of the bearing bars 324.

The lower chord 311 is slipped through the lower rectangular opening 325 of the compression elements 319 and the lower bearing legs 328 and locking legs 329 of the tension elements 320 are positioned to engage the lower bearing bars 324 of the compression elements 319 in a manner similar as the upper portions thereof.

The web is assembled in this manner on each side of the centerline of the truss so that the centerline has compression elements sloping downwardly away therefrom on each side of the truss. Thus, end legs 322 of adjacent compression elements 319 are disposed immediately on either side of the centerline of the truss.

When the web of the truss has been assembled in this manner, the compression elements and tension elements 319 and 320 are spread away from the centerline so as to insure that there is no slack between the elements present in the web, and the endmost tension elements 320 are connected to the end supports 335, as illustrated in FIG. 11. The compression elements 319 positioned at each end of the truss are constructed in two halves, the side legs 321 being separated at their midpoint, forming side legs 321a and 321]). Side legs 321a and 321b are oppositely threaded, and an internally threaded sleeve 350 having threads at each of its ends to match the threads of the side legs 321a and 321b, is threaded thereon. Of course, the sleeve 350 and side legs 321a and 321k function as a turnbuckle arrangement so that rotation of the sleeve 350 causes legs 321a and 3211) to move toward or away from each other, depending upon the direction of rotation of the sleeve 350. With this arrangement, when the web 318 is assembled as previously described, and if any slack remains in the truss, the turnbuckles of the endmost compression elements can be adjusted to take up the slack.

SIXTH EMBODIMENT FIG. 13 shows a sixth embodiment of the invention, which is similar to the fifth embodiment in that the upper and lower chords 410 and 411 are attached to each other by tension elements 420 and compression elements 419. While the compression elements 419 are identical to those of FIG. 9, the tension elements 420 comprise a tension leg 426 and locking legs 429 at each end thereof. Locking bars 430 extend across the locking legs 429 in the manner similar to the locking legs 330 of the previous embodiment. The locking legs 429 extend in opposite directions from the tension leg 426, at angles of approximately 60 thereto. The locking bars 430 are positioned on the inside of the angle disposed between the locking leg and the tension leg, and the locking bar is. constructed to engage the bearing bar 424 of the compression element 419 when the tension element and the compression element are assembled as shown in FIG. 13.

Referring to FIGS. 9-13, it can be seen that the fifth and sixth embodiment of the invention disclose a web that requires no slots in the upper and lower cords. Also, the locking legs 329 and 429, respectively, are positioned fiat against the upper and lower chords 310 and 311, or 410 and 411, respectively, and the bearing bars 324 and 424, respectively, are positively engaged with the tension elements. Thus, no amount of vibration or inadvertent adjustment will cause the compression and tension elements to disengage each other. Also, since steel is generally stronger in tension than it is in compression, tension elements 320 and 420 can be constructed with less strength characteristics than the compression elements 319 and 419, thereby economizing on the amount of metal utilized in the structure while retaining balanced strength characteristics in the web.

The trusses here disclosed are used in the usual way, by being suspended between a pair of bearing plates as shown in FIG. 9. Since the upper chords 10 and of FIGS. 1-3 and 5 have the transverse grooves 23 and 123 opening upwardly, the only metal portions which would obstruct nails, screws, or bolts being passed into the upper chords 10, 110 are the head bars 54, 54a and 154' which are plainly visible and can be avoided.

In a situation where the lower chord of the truss is to carry a woden structure, it is probably preferable to utilize the truss of FIGS. 1 and 2 or the truss of FIG. 8 since such a structure provides a wooden lower chord which is suitable for receiving nails, screws or bolts.

It is now seen that, by the construction heretofore described, quite inexpensive and easily assembled trusses are produced, the chord or chord members 10, 11, 110, 218, 310, 311, 410 and 411 being produced from conventional structural lumber and the web elements being formed from inexpensive rod material. The web members are each relatively short and are suitable for forming compact bundles for shipment; however, when assembled with their chords as heretofore described, the opposed hook members of adjacent web rods 50 and (FIGS. 1-8) engage their chords 10, 11 or 110 sidewise from opposite directions and are prevented from being disengaged therefrom, due to the fact that the shanks 51 or 151 are inter locked together adjacent the engaged chord 10, 11 or 110. The plates or blocks 21, 22, 27, 28, 121, 122, serve a number of functions. Primarily, these plates or blocks form a means by which the hooks of web rods 50 and 150 are spaced apart at the upper and lower surfaces of chords 10, 11 and 110. Furthermore, these plates or blocks prevent rotation of the rods 50, or 150 and recess the head bars 54, 5411, 154' below the surface of their associated chords so that the chords 10, 11 and 110 present uniform, fiat, outer surfaces for the receipt of flat surfaces thereon. The short plates or blocks 22, 28 and 122 also, in some instances, receive compressive forces transmitted from the web rods 50 and 150.

In the embodiments shown in FIGS. l-8, the hooks on the web rods serve to space the shanks inwardly of the edges of the chord members, and to align the shanks longitudinally of the truss. The end portions of the shanks prevent sidewise motion of the shanks, thereby maintaining the longitudinal alignment of the shanks within the confines of the chord members.

In the embodiments shown in FIGS. 9-13, no twisting forces are encountered in the web so that slots disposed in the chords are not required to prevent rotation of the elements of the web. Of course, the end legs 322 of the compression elements 319 project outwardly of the surfaces of the chords 310 and 311 so that a smooth surface is not encountered on the chords. Tccordingly, if it is desired to have a smooth nailable surface disposed above and below the truss, blocks or plates can be nailed, screwed or glued to the chords 310 and 311 in a manner similar to that shown in FIG. 1.

It will be obvious to those skilled in the art that many variations may be made in the embodiments chosen for the purpose of illustrating the present invention without departing from the scope thereof defined by the appended claims.

What is claimed as invention is:

1. A truss including an upper laterally extending chord and a lower laterally extending chord and a web extending therebetween, said web including a first series of sloped parallel web elements each surrounding both said chords and including bearing surfaces engaging the inner surfaces of a second series of oppositely sloped web elements and said second sloped web element extending between and connecting together adjacent ones of said first web elements at positions intermediate and alternately adjacent said upper and lower chords, said web elements of said second series of web elements are generally Z-shaped and each comprises an elongated center tension leg, oppositely extending locking legs disposed at each end of said center tension leg and a locking bar connected to each said locking leg for locking each of said second series of web elements to adjacent ones of said first series of web elements.

2. In a truss including an upper chord and a lower chord and a web extending between and connecting together said chords, said web comprising a series of first web members each extending downwardly away from the truss and including upper and lower end leg portions positioned respectively on the upper surface of the upper chord and the lower surface of the lower chord, side leg portions extending between and connecting together said upper and lower leg portions on opposite sides of said upper and lower chords, and upper and lower bearing members extending between said side leg portions adjacent the lower surface of the upper chord and the upper surface of the lower chord, and a series of Second web members each extending downwardly toward the truss and extending between and connecting together the upper and lower bearing members of adjacent ones of said first web members.

3. The invention of claim 2 wherein said second web members each comprise a Z-shaped strap with its upper and lower legs positioned between the upper bearing member and the upper chord and the lower bearing member and the lower chord, respectively, of adjacent ones of said first web members.

References Cited UNITED STATES PATENTS 805,762 11/1905 Thomas 52695 878,221 2/1908 Matthews 52695 995,437 6/1911 Casanova 52--226 1,554,224 9/1925 McGrath 52-693 X FOREIGN PATENTS 28,207 1913 Great Britain. 323,249 1957 Switzerland.

JOHN E. MURTAGH, Primary Examiner. 

